So you are saying that you would HAVE to stop at point C even if the winds were more favorable than planned and you COULD make point B with adequate fuel reserves?
I don't know the answer to your question but I look forward to the opinions. I do know that IAW the operation and rules (P91/135) that I fly under this would not be a factor and often end up changing the destination and/or fuel stops once enroute.

USMCFLYR